Food Allergies

symptoms of food allergy

*eyes* - redness - itching - tearing *nose* - congestion - rhinorrhea - sneezing *intestines* - cramping - diarrhea - mucous secretion - edema *cardiovascular* - dizziness - pale - blue color - weak pulse - fainting - shock *larynx* - edema - hoarseness *lungs* - wheezing - cough *stomach* - nausea - vomiting - cramping *skin* - hives - swelling - redness - itching - eczema

adverse food reactions (non-immunologic)

*toxic/pharmacologic* - bacterial food poisoning - heavy metal poisoning - scombroid fish poisoning - caffeine *nontoxic/intolerance* - lactase deficiency - galactosemia - pancreatic insufficiency - gallbladder/liver disease - gustatory rhinitis

latex-fruit syndrome

- 30-50% of those with latex allergy are sensitive to some fruits due to cross-reactive IgE - most common fruits: banana, avocado, kiwi, chestnut - can clinically present as anaphylaxis to fruit - warn latex-sensitive patients of potential cross-reactivity - some fruit-allergic patients may be at risk for latex allergy

the food allergy epidemic

- 32 million americans - 1 in 10 adults, 1 in 13 children (based on symptoms) - 42% children, 51% adults = anaphylaxis - higher number of children in lower age groups have allergies, but they outgrow it

how do allergens fit in a complementary infant feeding plan?

- begin feeding at 6 months of age, waiting is not recommended - complementary foods + allergenic foods should be fed together - avoid foods/beverages, with added sugars, high sodium - protein foods are important sources of iron, zinc, protein, choline, and LC PUFAs - iron, zinc, vitamin D, choline, potassium = under-consumed

food-associated exercise-induced anaphylaxis (EIA)

- can eat a food without a reaction and can exercise without a reaction - food ingestion followed by exercise (within 4 hours) can result in anaphylaxis - most common foods: wheat, oat, barley, rye, turkey, celery, soy, milk, shellfish, alcohol

pollen-food syndrome or oral allergy syndrome

- clinical features: rapid onset oral pruritus, rarely progressive - epidemiology: prior sensitization to pollens - key foods: raw fruits and vegetables - proteins that cross react with pollen proteins - heat labile (cooked food usually ok) birch = apple, carrot, celery, cherry, pear, hazelnut ragweed = banana, cucumber, melon grass = melon, tomato, orange mugwort = melon, apple, peach, cherry

factors that may lead to increased nutritional risk in food allergy

- cow's milk allergy - inadequate substitution/supplementation in the elimination diet - early onset food allergy - delayed or limited introduction of complementary foods - type of food allergic disorder - feeding difficulties or dysfunction - inability to manage food avoidance - additional non-allergy dietary restrictions

growth indices and impacting factors in children with food allergies

- cow's milk allergy had lower weight-for-height z scores than other food elimination - mixed IgE and non-IgE had lower height-for-age z scores than IgE mediated allergies - stunting was more common in children with food allergies than low weight or wasting, with 9% of the overall population stunted - growth parameters were significantly higher for weight for age, height for age, and BMI where dietitian/nutritional input was available

EAT trial

- early introduction of milk, egg, peanut, fish, wheat, or sesame - ITT: no significant difference in food allergy or skin prick tests between groups - PP: introducing peanut and cooked egg from 3 months of age, significantly less likely to have peanut and egg allergy

suspected food allergy: the why of testing

- history and epidemiologic considerations should guide test selection - why do we test? confirm suspicion of IgE mediated allergy, monitor tolerance development in IgE mediated allergy, tolerated foods generally need not be tested positive tests could not be clinically relevant = just because you get a positive result, does not mean you have an allergy because you need a reaction to occur

incidental ingredients

- major food allergen may not be omitted from the product label even if it is a minor ingredient - allergens not considered major may remain unidentified on product labels

what is the cause of nutritional problems?

- malnutrition found in a cohort - cause of malnutrition by dietician: suboptimal oral intake and limited food choices, knowledge deficit related how to introduce safe foods

precautionary allergen labeling

- may contain - manufactured in a facility - manufactured on shared equipment - voluntary, unregulated - this is an issue if unlabeled if the company has had issues with cross-contact

disorders not proven to be related to food allergy

- migraines - behavioral/developmental disorders - arthritis - seizures - IBD

FALCPA on labels

- milk - egg - wheat - soy - peanut - tree nuts* - fish* - crustacean shellfish* * = specific species must be listed need to use "real" name rather than scientific name; warning label

how to list major allergens

- parenthetically - contained statement - ingredient list with common name

testing of food allergies (the what & how)

- prick skin test (IgE) - serum-quantitative measurement of food specific IgE - component resolve diagnostics, based on allergen components - double blind placebo controlled food challenge - "gold standard"

non-IgE mediated food allergies

- protein-induced enterocolitis - protein-induced enteropathy - proctitis/proctocolitis - contact dermatitis - heiner's syndrome

LEAP trials

- recruited infants with eczema/egg allergy (at risk for peanut allergy) - relative risk reduction (negative cohort and positive cohort for skin prick test)

what is the nutritional impact of early allergic introduction?

- smooth puree: peanut butter, peanut flour, peanut powder, bamba > 5 years = whole nuts > 4 years = clumps/chunks of peanut butter LEAP: no choking episodes, whole peanut avoided, weekly target achieved; growth = no difference in weight/height/BMI/waist circumference/subscapular and triceps skin fold, nutrition = breastfeeding duration equivalent, micronutrient intake equivalent, carbohydrate intake lower in the introduction group due to less starch and sugar, fat intake was higher in consumption group, no difference in fruit and vegetable intake protein = equivalent intakes (higher intake of vegetable protein compared to animal protein)

IgE-mediated food allergies

- systemic - immediate gastrointestinal allergy - asthma/rhinitis - urticaria - morbilliform rashes and flushing - contact urticaria - oral allergy syndrome - latex-fruit syndrome - exercise-induced anaphylaxis - alpha gal

dietary elimination as diagnostic tool

- when chronic symptoms or delayed symptoms make determining the cause difficult - removal of the suspected allergen should result in significant improvement or remission of symptoms - followed by food challenge and recurrence of symptoms non-IgE mediated

FITS (2016)

8 years later, there were very low rates of reported peanut consumption across the study population

guidelines for food allergy prevention

AAP: no milk until 12 months, no egg until 2 years, no peanut, tree nuts, fish, shellfish until 3 years of age... in 2008, there is no convincing evidence for delaying the introduction of highly allergenic foods after 4-6 months of age for the prevention of allergy

immunologic food allergies

IgE-mediated (rapid onset, most common, multiple organ systems) non-IgE mediated (cell-mediated, delayed in onset, impacts GI tract, no testing of allergies)

updated allergy guidelines

NIAID: recommend early introduction of peanut in those at risk of peanut allergy AAP: no evidence that delaying allergenic foods beyond 4-6 months prevents atopic disease; early introduction of infant-safe forms of peanut will reduce peanut allergies dietary guidelines: begin complementary feeding around 6 months, risk of peanut allergy = introduce at 4-6 months, introduce potentially allergenic foods when other complementary foods are introduced consensus approach: introduce cooked egg and peanut-containing products to all infants, irrespective of their relative risk of developing peanut allergy, around 6 months of age (not before 4 months)

definition of anaphylaxis

WAO: a serious life threatening generalized or systemic hypersensitivity reaction, a serious allergic reaction that is rapid in onset and might cause death AAAAI/ACAAI: an acute life threatening systemic reaction with varied mechanisms, clinical presentations, and severity that results from the sudden release of mediators from mast cells and basophils EAACI: a severe life threatening generalized or systemic hypersensitivity reaction

what is true about precautionary allergic labeling?

according to FALCPA, precautionary allergic labeling is unregulated

food allergy

an adverse health effect arising from a specific immune response that occurs reproducibly on exposure to a given food

precautionary allergen labels (ex: may contain milk) for major allergens are required by law

false

dairy-free on non-dairy labeled foods are always safe for one with a milk allergy

false - dairy free = no definition - non-dairy is defined, but allows casein - must read ingredient list and contained statement

what tests can indicate a food allergy?

no test in isolation can predict a food allergy

the patient is positive for peanut allergy based on IgE test, has never consumed peanut/had an allergy, has mild eczema. does she have a peanut allergy?

peanut sensitized (positive test, but may or may not have allergy)

how are food allergies different from adverse reactions?

produces an immune response

what is a risk factor for peanut allergy?

severe eczema

which ingredients need to be avoided?

soy oil/lecithin = safe corn oil/syrup = safe sesame oil = avoid, not refined (sesame protein) peanut oil = avoid as if not highly refined may contain peanut

is peanut oil highly refined?

the way an oil is processed (highly refined or expeller pressed) is not required to be listed on the product label

goal of dietary management

to prevent acute and chronic food allergic reactions, while maintaining appropriate nutrition for growth and development dietician's focus: effective avoidance, nutritional adequacy

precautionary allergen labeling such as "may contain peanut" carries the same risk as "manufactured in a facility that handles peanut"

true cannot assess degree of risk based on the labeling